Universal seal for use with endoscopic cannula

ABSTRACT

A universal seal is shown with orbital movement of a center opening for use in endoscopic surgery. A two part seal housing encloses the universal seal in an annulus surrounding an insertion port. The outer periphery of the universal seal is clamped between the two parts at the outer edge of the annulus. An inner ring of the universal seal is free to move from side-to-side inside the annulus while maintaining rubbing contact with the upper and lower surfaces of the annuluses for vertical support. The seal housing and universal seal are mounted on a proximal end of a cannula which allows access therethrough for the endoscopic surgery. The center opening of the universal seal is in general alignment with the insertion port of the seal housing, but the center opening and inner ring may move from side to side when medical instruments are inserted through the insertion port, the center opening, and the cannula and moved from side to side.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/419,426 filed Apr. 21, 2003 now U.S. Pat. No. 7,169,130, which is acontinuation of U.S. application Ser. No. 09/422,414 now U.S. Pat. No.6,551,282 filed on Oct. 21, 1999, which is a continuation of U.S.application Ser. No. 09/027,754 now U.S. Pat. No. 5,989,224 filed Feb.23, 1998. The disclosure of each of these prior applications is herebyincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to seals for use in endoscopicsurgery and, more particularly, to a universal seal that seals againstdifferent sizes of medical instruments being inserted through a cannulainto the body while maintaining insufflation pressure, yet stillallowing for side to side motion of the medical instruments.

BACKGROUND OF THE INVENTION

As modern technology has developed, new surgical innovations havefollowed the technology. One of the techniques of modern surgery thathas rapidly grown in the last decade is the use of small openings in thebody through which access to the internal organs is obtained. While manydifferent titles to describe this technique have been used, probably themore common titles are laparoscopic surgery or endoscopic surgery. Otherpeople prefer more descriptive titles such as telescopic surgery orminimally invasive surgery. This entire area of surgical techniquesprobably developed the most in laparoscopic cholecystectomy, which isused to remove gall stones.

For the present application, because the most commonly used andcomprehensive term is endoscopic surgery, the term endoscopic surgerywill be used in this application to refer collectively to all of thesetypes of surgery. However, it should be realized that other terms can beused to describe the surgical technique.

In endoscopic surgery, a small cut is made in the skin and a sharpenedcannula or spike is then inserted through the fascia into a body openingsuch as the abdominal cavity. After removal of the spike from thecannula, the cannula will then allow access to the body opening such asthe abdominal cavity.

Typically, a gas is inserted through the cannula to insufflate the bodyopening. Once the first opening is made, a camera lens on the end of afiber optic cable can be inserted through the cannula that will allowthe monitoring of the internal parts of the body cavity. It is extremelyimportant that the body organs not be damaged when inserting anycannulas, spikes, or trocars into the body.

After access to the body opening is obtained by the insertion of thecannula, it is also important to maintain a seal along the centralopening of the cannula. If not, the gas used for the insufflation of thebody cavity will rapidly escape and it will be difficult to maintain asufficient cavity opening for the endoscopic surgery.

In the past, various types of seals have been developed to seal theupper part of the cannula opening. An example is shown in U.S. Pat. No.5,512,053, which patent is owned by the same assignee as the presentapplication. U.S. Pat. No. 5,512,053 provides a lip seal to maintain theinsufflation gas in the body cavity. However, once a medical instrumentis inserted through the lip seal, the gas can leak around the medicalinstrument and escape into the atmosphere. To provide a back up, asecond sliding seal with different size apertures has been provided toengage the medical instrument being inserted into the cannula andthrough the lip seal. Medical instruments vary in size, and the medicalinstruments will be moved form side to side during use in endoscopicsurgery. This side to side motion causes leakage of the gas around themedical instruments. Some type of seal is needed that will seal aroundmedical instruments of varying sizes and, at the same time, allow forlateral or side to side movement of the medical instrument duringendoscopic surgery.

Also, it is important that the seal have a memory to return to itsoriginal position after periods of use. In other words, if the doctorduring the operation is moving the medical instrument to one side, thereshould be a continual force trying to urge the medical instrument backto the center of the cannula opening.

To remedy the problem of different size medical instruments beinginserted through the cannula, U.S. Pat. No. 4,112,932 shows alaparoscopic cannula that has a rotating seal where different sizeopenings can be selected depending upon the size of instrument beinginserted into the cannula. While this is effective to some degree, itdoes not allow for side to side movement of the medical instrument andit does not allow for the rapid exchange of medical devices without alsorotating or spinning the seal.

A common seal that is in use today to seal surgical instruments such ascannulas, trocars, or similar devices is shown in U.S. Pat. No.5,407,433 to Loomas. The Loomas patent and its related patents allowssome side to side movement of the medical instruments, but has a rigidinternal ring on the seal that limits its effectiveness. The rigidinternal ring does not allow the seal to make a sealing relationshipwith the medical instrument as well as the present invention. Theinflexible nature of the internal ring does not provide as effective anurging force against the medical instrument to return the medicalinstrument to the center of the cannula. The Loomas seal is also muchmore complicated and expensive to manufacture than the present universalseal and does not provide as effective sealing as the present invention.

To overcome this problem of accommodating different sizes of medicalinstruments and to allow for side to side movement, many other UnitedStates patents have been issued to seal surgical instruments such ascannulas or trocars. Another example is U.S. Pat. No. 5,342,315 issuedto Rowe, which has a whole collection of different types of seals. Eachof these seals is much more complicated and expensive to manufacturethan the present invention and still is not as effective. The Rowepatent shows all types of reinforcing ribs and slots being cut in theseal, none of which are necessary with the present invention.

Other patents refer to their seal as a “universal seal” such as U.S.Pat. No. 5,628,732 to Antoon or U.S. Pat. No. 5,350,364 to Stephens.Again, both of these patents are much more complicated, expensive, anddo not do the job of the present universal seal. Applicants, who arevery familiar with the industry, does not know of any other seal that isas economical and inexpensive to manufacture as the present universalseal, but is as effective in allowing different size instrument to beinserted through a cannula and allowing side to side movement of themedical instrument, yet still maintaining air tight contact to hold theinsufflation gas inside the body cavity. The need exists for a universaltype of seal that can be used for any cannula or trocar device throughwhich access is obtained to body cavities for the purpose of performingendoscopic surgery, particularly while sealing against the surgicalinstruments being inserted through the cannulas or trocars into thebody.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a universal seal.

It is another object of the present invention to provide a seal forcannulas or other devices used in endoscopic surgery.

It is still another object of the present invention to provide for auniversal seal that can be used with cannulas or trocars, whichuniversal seal allows for side to side movement with different sizesurgical instruments when inserted therethrough, yet still maintainingan air tight seal to hold the insufflation gas inside the body.

It is yet another object of the present invention to provide a cannulawith an improved seal for sealing against the surgical instruments beinginserted through the cannula into the body cavity while still urging thesurgical instrument and the seal back to the center of the cannula dueto the memory of the elastomeric material.

It is still another object of the present invention to provide auniversal seal that can seal against medical instruments of differentdiameters as they are inserted through a cannula or trocar duringendoscopic surgery and still maintain the seal during side to sidemovement of the medical instrument.

The universal seal is shown in a preferred embodiment in combinationwith a reusable cannula. The reusable cannula is made from a metalmaterial and is connected to a lip seal housing for a lip seal. Aninsufflation port connects through the lip seal housing into the centralpassage of the reusable cannula below the lip seal. Above the lip sealhousing is an adapter so that different devices or seals may be attachedto the lip seal housing.

Above the adapter is a universal housing, which maintains a universalseal between a top and bottom portion of the universal seal housing. Thetop and bottom portions form an annulus therebetween that surrounds aninsertion port in the universal seal housing. An outer ring of theuniversal seal is compressed at the outer edge of the annulus betweenthe bottom and top portions of the universal seal housing. An inner ringof the universal seal is free to move back and forth inside of theannulus while maintaining rubbing contact with the top and bottomportions of the universal seal housing which forms the annulus. A smallopening is in the center of the universal seal.

Because the universal seal is made from elastomeric material, as medicalinstruments of different diameters are inserted through the insertionport into the small opening of the universal seal, the small opening inthe universal seal will expand to accommodate the different size medicalinstruments up to a predetermined limit. If the medical instrument movesfrom side to side, the center ring of the universal seal will deform andmove inside of the annulus to allow for side to side movement of themedical instrument while still maintaining contact with the medicalinstrument. The universal seal will have a tendency to self center thatis caused by a combination of (a) memory of the elastomeric material,(b) gas pressure on the underside of the universal seal, and (c)geometry of the universal seal. This combination creates what could becalled an annular spring.

Several different embodiments of the universal seal are shown. Also, theuniversal seal with the seal housing may be attached to other types ofmedical devices such as trocars for allowing entry into the body forendoscopic surgery.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of the present invention beingused with a reusable cannula.

FIG. 2 is a cross-sectional view of FIG. 1, when assembled, taken alongsection lines 2-2.

FIG. 3 is an elevated cross-sectional view of the present inventionbeing used with a locking trocar.

FIG. 4 is a partial cross-sectional view of a cannula utilizing thepresent invention with the medical instrument being moved to the rightside.

FIG. 5 is a partial cross-sectional view of a cannula utilizing thepresent invention with the medical instrument being moved to the leftside.

FIG. 6 is an enlarged cross-sectional view of the universal seal asmanufactured.

FIG. 7 is a cross-sectional view of the universal seal in its normalposition when installed in the universal seal housing.

FIG. 8 is an alternative embodiment of the universal seal of the presentinvention.

FIG. 9 is another alternative embodiment of the universal seal of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2 in combination, the universal seal of thepresent invention is shown in a reusable cannula referred to generallyby reference number 10. The cannula 12 has a slanted cut lower distalend 14 from which a spike or similar instrument (not shown) may extend.

An enlarged upper portion 16 of the cannula 12 has upper internalthreads 18 for threadably connecting to lower threads 20 of a lip sealbody 22.

The lip seal body 22 has a port 24 through which insufflation gas isinserted. The insufflation gas 30 is directed downward through thecannula 12 into the body of the patient.

A lip seal 26 is located on an internal shoulder 28 of the lip seal body22. A slot 30 is cut in the lip seal 26, which slot 30 may be openedupon the insertion of medical instruments.

A snap cap 32 snaps onto the upper portion of the lip seal body 22 tosecurely hold the lip seal 26 in position. The snap cap 32 may be heldto the lip seal body by any conventional means such as snap posts (notshown). Around the upper part of the snap cap 32 is an elastomeric ring34 that provides a good fit with the adapter 36. The adapter 36, alsocalled a Chiulli adapter, is used so that access can be obtained to thecannula for the removal of body tissue. It is important not to have togo through any further seals in reaching into the body and removingirregular objects.

While the adapter 36 can be of any particular configuration, in thepresent preferred embodiment, it is of an elongated shape and has amating shoulder/edge 38. The mating shoulder/edge 38 is received into amating cavity 40 formed in the bottom 42 of the universal seal housing44. The connection between the adapter 46 and the bottom 42 of theuniversal seal housing 44 is an air tight seal that will not allowinsufflation gas to escape therethrough. A circular opening 46 is in thetop of the bottom 42 of the universal seal housing 44. The top 48 of theuniversal seal housing 44 connects to the bottom 42 by any conventionalmeans. Therebetween is located the universal seal 50, which will bedescribed in more detail subsequently. In this preferred embodiment, thebottom 42 and the top 48 are held together by snap posts 52 snappinginto holes 54 to hold the universal seal housing 44 together.

Referring to FIG. 2, it can be seen that the top portion 48 has anangular undercut 56 formed therein that is just above the circularopening 46 in the bottom 42 of the universal seal housing 44. Theangular undercut 56 with the circular opening 46 forms an annulus inwhich a roll or bellows 58 of the universal seal 50 is located. An outerring 60 of the universal seal 50 is pressed between the bottom 42 andthe top 48 in a solid sealing relationship. The outer ring 60 is heldvery securely in place.

An inner ring 62 of the universal seal 50 is located inside of the rollor bellows 58. The inner ring 62 is free to slide back and forth insliding contact with the bottom side of the top 48 or the circularopening 46 of the bottom 42 of the universal seal housing 44. In themiddle of the universal seal 50 is located an opening 64 through whichmedical instruments (not shown) may be inserted. The opening 64 is inalignment with the center of the central passage 66 which extendsthrough the universal seal housing 44, adapter 36, snap cap 32, lip sealbody 22, and cannula 12.

The inner ring 62 prevents the universal seal 50 from being pushed intothe central passage 66 when inserting a large diameter instrument, orfrom being pulled into the central passage 66 when removing a largediameter instrument.

Referring now to FIGS. 4 and 5 in combination, an elevated partialcross-sectional view of the reusable cannula with the universal seal 50is shown. A medical instrument 68 is inserted through the opening 64 ofthe universal seal 50. As the medical instrument 68 is moved to theright hand side as illustrated in FIG. 4, the inner ring 62, while stillmaintaining sliding contact with the top portion 48 and the bottomportion 42, moves to the right as the opening 64 moves to the right. Theroll or bellows 58 of the universal seal 50 compresses in the right handdirection and elongates in the left hand direction. Also, the inner ring62 being deformable may deform as the medical instrument 68 moves to theright. The medical instrument 68 will extend down through the opening 64of the universal seal 50 and through the slot 30 in the lip seal 26.While it is not shown in the drawings, the slot 30 has a tendency toallow insufflation gas to escape on either end of the slot adjacent tothe medical instrument 68. Therefore, it is important that the universalseal 50 have a good sealing relationship with the medical instrument 68.

As the medical instrument 68 moves to the left as shown in FIG. 5, theopening 64 moves to the left. Likewise, the inner ring 62 moves to theleft as well. Again, the roll or bellows 58 on the universal seal 50tends to compress to the left and expand to the right. Again, a goodsealing relationship is maintained with the medical instrument 68.

As can be seen in FIGS. 2, 3, 4 and 5, the universal seal 50 has adownward conical shape 55 that allows for ease of insertion of a medicalinstrument without tearing or damage. Gas pressure against the downwardconical shape 55 also helps insure an air-tight seal against a medicalinstrument.

While in the present view, the medical instrument is shown as a surgicalcutting device, any other type of medical instrument may be insertedsuch as surgical devices, lens on the end of fiber optic links, clipappliers, just to name a few of the medical instruments.

Referring to FIG. 6, the universal seal 50 is shown as it comes out ofthe mold and as it would normally appear. In this enlarged view, theconfiguration of the outer ring 60, inner ring 62, and opening 64 isclearly visible.

As the universal seal 50 is installed in the universal seal housing 44,it will assume the configuration as shown in FIG. 7 with the roll 58 asclearly shown. The outer ring 60 may be compressed when installed.Otherwise, FIG. 7 is an enlarged representation of the view of theuniversal seal 50 when in operation.

Referring to FIG. 3, an alternative use for the universal seal 50 isshown in a trocar arrangement, the trocar being generally referred towith reference number 70. The trocar 70 as shown in FIG. 3 is a lockingtrocar that has a molly bolt type of arrangement for an outer cylinder72. A molly bolt 74 has a lever 76 that is pivoted up or down, whichcauses the gear 78 on the molly bolt to pivot. The gears 78 of the mollybolt engages the corresponding outer cylinder gears 80 which are on thetop of the outer cylinder 72.

The outer cylinder 72 moves up and down as the lever 76 is moved downand up. When the outer cylinder 72 is moved down, expandable members 82extend outward as shown in FIG. 3. In that manner, the outer skin orfascia of the body in which the trocar 70 is being inserted ismaintained solidly in position between the retaining ring 84 and theexpandable members 82. If the outer cylinder 72 is moved up by pivotingthe lever 76 down, the expandable members 82 will close so that theouter cylinder 72 appears as an ordinary cylinder.

The outer cylinder 72 is riding on an inner cylinder 86 which issecurely mounted into position at the top by housing 88. The housing 88may be made from two pieces of injection molded plastic that are fusedor snapped together. Inside of the housing 88 is a lip seal housing 90in which the lip seal 92 is located.

Above the housing 88 and the lip seal housing 90 is located theuniversal seal 50 and universal seal housing 44 as previously describedin connection with FIGS. 1 and 2. The configuration of the universalseal 50 and universal seal housing 44 is the same as previouslydescribed; therefore, it will not be described again in connection withthe trocar arrangement of FIG. 3.

Referring now to FIGS. 6 and 7 in combination, FIG. 6 shows theuniversal seal 50 as it comes out of the mold in which the elastomericmaterial forming the universal seal 50 is cast. When the universal seal50 is put in the universal seal housing 44, it will be pushed down as isillustrated in FIG. 7. The inner ring 62 pushes down as is pictoriallyillustrated in FIGS. 2 and 5.

Referring now to FIG. 8, a modified universal seal 94 is shown which canstill fit in the universal seal housing 44. The modified universal seal94 has an outer ring 96 which is secured in position between the bottom42 and top 48 of the universal seal housing 44. An inner ring 98 isconnected by an air bladder 100 with outer ring 96. Extending inwardfrom inner ring 98 is upper membrane 102 and lower membrane 104, both ofwhich have a center opening 106.

The inner ring 98 will be in rubbing contact with the bottom 42 and top48 of the universal seal housing 44. The modified universal seal 94 willflex generally in the same way as the universal seal 50 described in thepreferred embodiment with the inner ring 98 flexing as the medicalinstrument inserted therethrough may move from side to side. Also, themodified universal seal 94 will accommodate varying sizes of medicalinstruments being inserted.

Referring to FIG. 9, a further modification of the universal seal isshown and is referred to generally by reference numeral 108. Themodified universal seal 108 still has an outer ring 110 that is securelyclamped into position by a universal seal housing 44. However, in themodified version shown in FIG. 9, the inner ring has been replacedentirely by an annular air bladder 112. The outer portion of the annularair bladder 112 is formed integral with the outer ring 110. Extendinginward from the annular air bladder 112 to a central opening 114 is thecenter membrane 116. Again, as described with the prior embodiments, theannular air bladder 112 will allow for side to side movement of themedical instruments being inserted through the central opening 114. Theannular air bladder 112 will continue to urge the medical instruments,if it moves in a side to side manner, back toward the center of thecannula passage.

1. A surgical access instrument for permitting access to body tissue,which comprises: a member positionable within body tissue, the memberhaving an opening to access the body tissue and permit passage of anobject, and defining a longitudinal axis, the member defining proximaland distal ends; a seal housing mounted to the proximal end of themember, the seal housing including internal opposing surfaces; and aseal mounted at least partially disposed within the seal housing, theseal including an outer portion and an inner seal portion extendingradially inwardly from the outer portion for forming a substantial sealabout the object, the inner seal portion including a first seal membranecomprising an elastomeric material and a second seal membrane comprisingan elastomeric material and being longitudinally spaced from the firstseal membrane and in general longitudinal alignment therewith, the innerseal portion having a deformable ring connecting the first seal membraneand the second seal membrane, the first seal membrane and the secondseal membrane each having inner surfaces defining passages for receptionand passage of the object with the inner surfaces of the first andsecond seal membranes engaging the object in substantially sealedrelation therewith, the inner seal portion of the seal being dimensionedand adapted for radial movement relative to the longitudinal axis andhaving opposed surfaces in sliding contacting relation with the internalopposing surfaces of the seal housing, the outer portion including anenclosed annular bladder disposed radially outward of the deformablering and adapted to bias the passages of the inner seal portion to begenerally aligned with the longitudinal axis of the member whilepermitting movement of the passages of the inner seal portion in alateral direction with respect to the longitudinal axis upon offsetmanipulation of the object.
 2. The surgical access instrument accordingto claim 1 wherein the first seal membrane is generally planar and isarranged in general orthogonal relation with the longitudinal axis. 3.The surgical access instrument according to claim 2 wherein the secondseal membrane is generally planar and is arranged in general orthogonalrelation with the longitudinal axis.
 4. The surgical access instrumentaccording to claim 3 wherein the seal is monolithically formed.
 5. Thesurgical access instrument according to claim 2 wherein the second sealmembrane defines a general tapered configuration.
 6. The surgical accessinstrument according to claim 1 wherein the passages are aperturesextending through the first and second seal membranes.
 7. The surgicalaccess instrument according to claim 1 wherein the member includes acannula adapted for insertion through the abdominal cavity.
 8. Thesurgical access instrument according to claim 1 wherein the outerportion further includes an outer ring, the enclosed annular bladderbeing interposed between the outer ring and the deformable ring.
 9. Thesurgical access instrument according to claim 8 wherein the outer ringis secured to the seal housing in sealed relation therewith.
 10. Thesurgical access instrument according to claim 1 wherein the deformablering of the inner seal portion defines the opposed surfaces in slidingcontacting relation with the internal opposing surfaces of the sealhousing.
 11. A surgical access cannula for permitting access to bodytissue, which comprises: a cannula member positionable within bodytissue and defining a longitudinal axis, the cannula member having alongitudinal opening to permit passage of an object; and a monolithicseal mounted within the cannula member, the monolithic seal including: afirst generally planar seal membrane; a second generally planar sealmembrane longitudinally spaced from the first seal membrane, each of thefirst and second seal membranes having inner surfaces defining anaperture for receiving the object, the inner surfaces dimensioned andpositioned to transition between a first position corresponding to anopen condition of the aperture in the absence of the object and a secondposition to engage the object in substantial sealed relation therewith;a connecting ring interconnecting the first seal membrane and the secondseal membrane; and an enclosed annular bladder disposed radially outwardfrom the connecting ring.
 12. The surgical access cannula according toclaim 11 wherein each of the first and second seal membranes arearranged in general orthogonal relation with the longitudinal axis. 13.The surgical access cannula according to claim 11 wherein the monolithicseal comprises an elastomeric material.
 14. The surgical access cannulaaccording to claim 11 wherein the connecting ring is at least partiallydeformable during manipulation of the object.
 15. The surgical accesscannula according to claim 14 wherein the connecting ring comprises andelastomeric material.
 16. A surgical access cannula according to claim11 wherein the cannula member includes a seal housing having internalopposing surfaces, the sealing member at least partially disposedbetween the internal opposing surfaces, the connecting ring beingdimensioned and adapted for radial movement within the seal housing andhaving opposed surfaces in sliding contacting relation with the internalopposing surfaces of the seal housing.
 17. A surgical access instrumentfor permitting access to body tissue, which comprises: a cannulapositionable within body tissue, the cannula having an opening extendingtherethrough to access the body tissue and permit passage of an objecttherethrough, the cannula defining a proximal end, a distal end, and alongitudinal axis; a seal housing located about the proximal end of thecannula, the seal housing including internal opposing surfaces; and amonolithically formed sealing member mounted within the seal housing,the sealing member including an outer ring, an outer seal portion, aninner ring, and an inner seal portion; the outer portion extendingradially inward from the outer ring, the inner ring being radiallyspaced inward from the outer ring and connecting the outer seal portionto the inner seal portion, the inner seal portion extending radiallyinward from the inner ring, the inner seal portion including a firstseal membrane and a second membrane, the first membrane extendingradially inward from the inner ring, the second seal membrane extendingradially inward from the inner ring at a longitudinally spaced distancefrom the first seal membrane and in general longitudinal alignmenttherewith, the inner ring connecting the first seal membrane and thesecond seal membrane, the inner ring having opposed surfaces in slidingcontacting relation with the internal opposing surfaces of the sealhousing, the first seal membrane and the second seal membrane eachhaving inner surfaces defining open passageways for reception andpassage of the object, the first and second seal membranes adapted toengage in substantially sealed relation therewith, the outer portionbeing adapted to bias the passageways of the inner seal portion to begenerally aligned with the longitudinal axis of the cannula whilepermitting movement of the passageways of the inner seal portion in alateral direction with respect to the longitudinal axis upon offsetmanipulation of the object.
 18. The surgical access instrument accordingto claim 17 wherein the outer seal portion includes a biasing memberbeing adapted to normally bias the inner ring toward a position wherebythe passageways are in general alignment with the longitudinal axis. 19.The surgical access instrument according to claim 18 wherein the biasingmember includes a fluid bladder.
 20. The surgical access instrumentaccording to claim 18 wherein the biasing member includes an undulatingmember.
 21. The surgical access instrument according to claim 17 whereinthe inner ring is at least partially deformable during manipulation ofthe object.
 22. The surgical access instrument according to claim 17wherein the second membrane comprises an elastomeric material.
 23. Thesurgical access instrument according to claim 17 wherein the firstmembrane comprises an elastomeric material.
 24. The surgical accessinstrument according to claim 17 wherein the first seal membrane isgenerally planar and is arranged in general orthogonal relation with thelongitudinal axis.
 25. The surgical access instrument according to claim17 wherein the second seal membrane is generally planar and is arrangedin general orthogonal relation with the longitudinal axis.